# `html_classes`

New in version 2.12: The `html_classes` function was added in Twig 2.12.

The `html_classes` function returns a string by conditionally joining class names together:

    <p class="{{ html_classes('a-class', 'another-class', {
        'errored': object.errored,
        'finished': object.finished,
        'pending': object.pending,
    }) }}">How are you doing?</p>

Note

The `html_classes` function is part of the `HtmlExtension` which is not installed by default. Install it first:

    $ composer req twig/html-extra

Then, use the `twig/extra-bundle` on Symfony projects or add the extension explictly on the Twig environment:

    use Twig\Extra\Html\HtmlExtension;

    $twig = new \Twig\Environment(...);
    $twig->addExtension(new HtmlExtension());